The initial astronaut selection criteria issued by the National Aeronautics and Space Administration required jet pilot experience for all applicants. As a result, Army personnel were not eligible for astronaut duty. Although the criteria later changed to allow scientist astronauts, it was not until 1991 that two Army officers would serve together aboard the Space Shuttle.On Nov. 24, 1991, Lt. Col. James Voss and Chief Warrant Officer 3 Thomas Hennen, two members of a six person crew, began their seven day mission aboard the Space Shuttle Atlantis, marking the first time that two Army personnel had flown aboard the same shuttle flight. STS-44 also marks another significant first as Hennen was the first, and remains the only, warrant officer to fly in space.STS-44 was the ninth dedicated Department of Defense shuttle flight. On the first day, the crew addressed the primary mission launching a 5,200 pound Defense Support Program or DSP satellite, with an attached Inertial Upper Stage. Part of the Air Force's satellite early warning system, the DSP was designed to detect and report on real-time missile launches, space launches and nuclear detonations.Despite a curtailed flight due to a malfunctioning Inertial Measurement Unit, the crew was able to complete most of the scientific and engineering experiments. As identified by NASA, these included sensor calibrations for the Air Force Maui Optical system and a variety of efforts to monitor, measure and document cosmic radiation ("energy loss spectra, neutron fluxes and induced radioactivity") and gamma rays.The crew also conducted a number of medical experiments, part of the Extended Duration Orbiter Medical Project, which sought to assess various efforts devised to counteract the adverse effects of prolonged weightlessness.While Voss participated in a variety of experiments, Hennen focused upon Terra Scout. Trained in imagery analysis, terrain and aerial observations and geology, Hennen was selected in August 1989 to serve as a primary payload specialist for the Terra Scout experiment. Terra Scout involved the onboard observation and analysis of selected sites by Hennen who had "intensively studied the sites to be observed." Each site package included maps and photographs and large resolution panels. The grid pattern on the panels were designed to help assess the resolution limits from space.The Military Man in Space or M88-1 tri-service experiment performed a similar function. Focusing upon military exercises or mobile sea and/or ground assets, M88-1 sought to assess a person's visual and communications skills -- to observe and relay this data in near real-time to tactical personnel in the field. During this shuttle flight the M88-1 experiment utilized specialized optics and camera to collect high-resolution digital imagery which could then be stored and reviewed aboard the shuttle, orbiting at 195 nautical miles above the Earth, and relayed to the ground.Hennen began his Earth observations with the Spaceborne Direct-View Optical System, or SPADVOS, on the second day of the flight. On the next day, Hennen focused on two specific targets -- Learmouth, Australia and Ford Island, Hawaii. An error with the SPADVOS and weather issues postponed a review of four additional locations. With the SPADVOS problem rectified, Hennen continued his studies on the third day with sites in South Africa, the Indian Ocean and Malaysia.Multiple scouting opportunities were planned for each of the ten days that STS-44 was scheduled to be on orbit. Among the urban and rural sites selected for observation by Terra Scout and M88-1 were Brisbane, Australia; Cape Canaveral, Florida; Pearl Harbor, Hawaii; the U.S. Embassy in Manila, The Philippines; Midway Island; Christmas Island; Chase Field, Texas; Honduras; the Strait of Malacca; and Yucatan, Mexico.Weather conditions on Earth, however, obscured some of the intended targets. While both methods experienced minor equipment issues, they both achieved success by gathering important data on the equipment, the skillsets needed and the man-in-the-machine relationships. STS-44 returned to Earth on Dec. 1, 1991 landing at Edwards Air Force Base, California, at 2:34 p.m.